Fertile Days?

Has anyone gotten pregnant on days other than their fertile days? Glow says today is my peak and that I'll probably ovulate tomorrow but I'm almost sure I have already ovulated on the 5th . On the 4th I was having light pains during sex and on the 5th I had been having pains near my cervix and slight back pains and later that day my SO and I BD . It was soo painful. But I let him finish . The next day I had mild cramping, mild headaches , I slept all day. And today I'm experiencing gas a lot of it, mild cramps . Very tired , and I'm never satisfied with food. Help? According to glow AF suppose to arrive on the 19th .